SMSC USB4640i ユーザーズマニュアル

High Speed Inter-Chip USB 2.0 Hub and Flash Media Controller

SMSC USB4640/USB4640i

49

Revision 1.0 (06-01-09)

7:0

PRTM3

PortMap register for port 3.

When a hub is enumerated by a USB host controller, the hub is only 

permitted to report how many ports it has; the hub is not permitted to select 

a numerical range or assignment. The host controller will number the 

downstream ports of the hub starting with the number '1', up to the number 

of ports that the hub reported having. 

The host's port number is referred to as “logical port number” and the 

physical port on the hub is the “physical port number”. When remapping 

mode is enabled (see PRTMAP_EN in Register 08h: Configuration Data 

Byte 3) the hub's downstream port numbers can be remapped to different 

logical port numbers (assigned by the host).

The OEM must ensure that contiguous logical port numbers are 
used, starting from number ‘1’ up to the maximum number of 
enabled ports; this ensures that the hub's ports are numbered in 
accordance with the way a host will communicate with the ports.

6:0

Reserved

Reserved.

Bit [7:4]

‘0000’

Reserved

‘0001’

Reserved

‘0010’

Reserved

‘0011’

Reserved

‘0100’

to

‘1111’

Illegal; Do not use

Bit [3:0]

‘0000’

Physical port 3 is disabled

‘0001’

Physical port 3 is mapped to Logical port 1

‘0010’

Physical port 3 is mapped to Logical port 2

‘0011’

Physical port 3 is mapped to Logical port 3

‘0100’

to

‘1111’

Illegal; Do not use